Storage battery charging station

ABSTRACT

A charging station ( 1 ) for a rechargeable battery ( 5 ) that can be electrically and physically connected to the rechargeable battery ( 5 ). The charging station ( 1 ) has charger electronics ( 2 ) in a charger housing ( 3 ) and an electrical and physical contact interface ( 4 ) for the battery ( 5 ). An air blower ( 6 ) producing an air current (L) through two air vents ( 7   a   , 7   b ) is arranged in the charger housing ( 3 ). The air vent ( 7   a ) of the physical contact interface ( 4 ) is spatially associated with the battery ( 5 ) and the charger electronics ( 2 ) is heat-transfer arranged in the air current (L). In the cooling process, in a first stage, an air volume (V) at cooling temperature CT is moved past heat-transferringly into/onto the battery and, in a second stage, the air volume (V) at an intermediate temperature IT&gt;CT permeates the charger housing ( 2 ) containing the charging electronics ( 2 .).

BACKGROUND OF THE INVENTION

[0001] The invention relates to a charging station for a rechargeablebattery that is structurally and electrically compatible with thebattery, such as a storage battery module for cordless hand toolmachines. In modern rechargeable batteries, high energy densities can becharged in a brief period using a charging station, whereby the batteryheats up significantly. An important field of application of suchhigh-density energy rechargeable batteries are storage battery modulesfor cordless hand tool machines such as screwing drills, combinationhammers, hand circular saws, etc. In addition, the charger electronicsof the charging station also heat up significantly due to thetransformation of the high output.

[0002] EP 1178557 discloses a charging station for a rechargeablestorage battery module for cordless hand tool machines that can beelectrically and structurally connected to it. The charging station hascharging electronics, in a charger housing, with an electrical andstructural contact interface for the storage battery module. A blower isarranged in the charger housing. Optimally, a cooling/heating system isarranged downstream of the airflow outlet, between two air vents. An airvent on the airflow outlet side is associated with the structuralcontact interface of the storage battery module. There is no activecooling of the charger electronics arranged external to the air flow inthe housing corners or in separate housing sections. The air can,however, be pre-warmed by waste heat from the charger housing, whichrestricts the airflow before it cools the storage battery module. Thewarmed air from the storage battery module is discharged unused into theenvironment.

SUMMARY OF THE INVENTION

[0003] The object of the invention is to provide a process and aconfiguration for efficient cooling of the battery and the chargingelectronics.

[0004] This object is essentially achieved, in accordance with theinvention, by a charging station for a rechargeable battery that can beconnected structurally and electronically with the battery. The chargingstation has a charger electronics in a charger housing with anelectrical and physical contact interface for the battery, wherein anair blower for producing an airflow through two air vents is arranged inthe charger housing, wherein an air vent is spatially associated withthe physical contact interface of the battery and wherein the chargerelectronics are arranged for heat transfer in the air current.

[0005] The arrangement of both the battery and the charger electronicsin series, in a common heat-transferring air current, cools efficiently,because, along with a constant cooling surface and the temperaturedifference, the flow rate is also involved in the heat transmission.

[0006] It is also advantageous that the air vent spatially associatedwith the physical contact interface of the battery is arranged at theflow inlet side. By the association of the flow inlet side air vent withthe battery, the air warmed by the battery initially arrives in thecharger housing with the air blower, where it then cools the chargerelectronics and is then discharged to the environment.

[0007] The air blower is advantageously arranged between the air vent onthe flow inlet side and the charger electronics, whereby the chargerelectronics arranged in the high-pressure path does not contribute tothe pressure drop in the low-pressure path, in which the battery issituated. As a result, a strong flow is achieved.

[0008] The air vent on the flow inlet side advantageously formsmultiple, surface distributed air inlet points, which are spatiallyassociated with cooling vents of the battery, whereby the cooling airmass can be distributed to individual cells within the battery.

[0009] Advantageously, a pressure chamber with a low flow resistance isprovided between the air blower and the air inlet points. This permitsuniform distribution of the air volume between separate cells of thebattery.

[0010] The air vent on the flow inlet side is advantageously arranged inthe upper part of the charging station, wherein with expedient set-up ofthe charging station, less dust is picked up in the air current, whichis particularly advantageous in polluted work sites.

[0011] Essentially, the cooling process of a charging station for arechargeable battery that can be physically and electrically connectedto the battery moves a volume of air of an air current produced by anair blower arranged in the charger housing of the charging station. Inan initial process step, the air volume with a cooling temperature KT ismoved past or into the battery while transferring heat. In a secondprocess step, the air volume with an intermediate temperature IT>CTpermeates the charger housing having charging electronics.

[0012] For one and the same air volume in the air current, differentcooling heat transfers form due to the temporal sequence of theheat-transferring arrangement of the battery and the chargingelectronics. The heat transfers depend on the temperature difference.Since the permissible surface temperature of the charger electronicsessentially lies above the temperature of the battery, an air volumetaken from the environment and having a cooling temperature CT [KT],initially, optimally cools the battery and then at the intermediatetemperature IT [ZT] adequately cools the charging electronics before itis again discharged to the environment at the waste heat temperature WT[AT]. Thus, the overall available streaming air volumes are takenadvantage of for efficient cooling.

BRIEF DESCRIPTION OF THE INVENTION

[0013] The preferred embodiment of the invention is described below withreference to the drawing, wherein FIG. 1 shows a charging station withstorage battery pack according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0014]FIG. 1 shows a charging station 1 having a charging electronics 2in a charger housing 3 that is physically and electrically connected toa rechargeable battery 5, in the form of a storage battery module havinga plurality of cells 11, by an electrical and physical contact interface4. An air blower 6 is arranged in the charger housing 3. The blower 6produces an air current L through two air vents 7 a, 7 b. The chargerelectronics 2 are heat-transfer arranged in the air current.

[0015] The air vent 7 a, on the flow inlet side, is spatially associatedwith the physical contact interface 4 of the battery. The air blower 6is arranged between the air vent 7 a, on the flow inlet side, and thecharging electronics 2. The air vent 7 aon the flow inlet side has aplurality of surface-distributed air inlet points 8. Eachsurface-distributed air inlet point 8 is spatially associated withcooling vents 9 in the module housing 12 of the battery. A pressurechamber 10 having low flow resistance is arranged between the air blower6 and the air inlet points 8.

[0016] The cooling process moves a hypothetical air volume V along anair current L produced by the air blower 6. The air volume V at acooling temperature CT [KT] relative to the environment U moves past thebattery 5 in a heat-transfer fashion and then permeates charger housing3 containing a charger electronics heat-transfer arranged in an aircurrent L at an intermediate temperature IT>KT, before it is releasedinto the environment U at a waste heat temperature WT [AT].

What is claimed is:
 1. A charging station for a rechargeable battery (5)that can be physically and electrically connected to the battery (5)having charger electronics (2) in a charger housing (3) and anelectrical and physical contact interface (4) for the battery (5),wherein an air blower (6) is arranged in the charger housing (3) forproducing an air current (L) through two air vents (7 a, 7 b), whereinone air vent (7 a) is associated with the physical contact interface (4)of the battery (5), and wherein the charger electronics (2) isheat-transfer arranged in the air current (L).
 2. The charging stationof claim 1, wherein the physical contact interface (4) of the battery(5) is spatially associated with an air vent (7 a) on a flow inlet side.3. The charging station of claim 1, wherein the air blower (6) isarranged between the air vent (7 a) on a flow inlet side and the chargerelectronics (2).
 4. The charging station of claim 3, wherein the airvent (7 a) on the flow inlet side forms a plurality ofsurface-distributed air inlet points (8) each associated with coolingvents (9) of the battery (5).
 5. The charging station of claim 3,wherein a pressure chamber (10) having low flow resistance is arrangedbetween the air blower (6) and the air inlet points (8).
 6. The chargingstation of claim 1, wherein the air vent (7 a) on the flow inlet side isarranged in an upper section of the charging station (1).
 7. A coolingprocess for a charging station (1) for a rechargeable battery (5) thatis electrically and physically connected to the battery (5), wherein anair volume (V) of an air current (L) is moved by an air blower (6)arranged in the charger housing (3) of the charging station (1),comprising, a first step, wherein the air volume (V) at a coolingtemperature CT is moved heat-transfer into the battery (5), and, in asecond step, the air volume (V) at an intermediate temperature IT>CTpermeates the charger housing (3) containing the charger electronics(2).